Exposure to biological maternal sounds improves cardiorespiratory regulation in extremely preterm infants

The Impact of Video Calling Between Preterm Infants and Their Mothers on the Physiological Parameters of Infants and Mother-Infant Bonding

PURPOSE

This study aimed to determine the effect of video calling between preterm infants treated in the neonatal intensive care unit (NICU) and their mothers on the physiological parameters of infants and mother-infant bonding.

BACKGROUND

Preterm infants need prolonged treatment in the NICU, and their families may have difficulty seeing their babies during this treatment process.

METHODS

This is a prospective, randomized-controlled, experimental study. The study sample consisted of 75 preterm infants and their mothers. The data were collected using a maternal introductory information form, a preterm infant introductory information form, a preterm infant physiological parameters follow-up form, and the Mother-Infant Bonding Scale (MIBS). The study included 3 study groups: the video call group, the video call with lullaby group, and the control group. Video calls between preterm infants and their mothers were made through Zoom for 5 to 10 minutes daily for 7 days. The mothers filled out the MIBS online before and on the 7th and 30th days of the study.

RESULTS

Preterm infants in the video call and the video call with lullaby groups had higher MIBS mean scores on the 7th and 30th days of the study than their pretest MIBS scores. Preterm infants in the video call and the video call with lullaby groups had statistically significantly higher MIBS mean scores on the seventh day of the study than those in the control group. At the end of the 7-day study period, there was an improvement in the physiological parameters of preterm infants in the video call group and the video call with lullaby group compared with those in the control group, and this relationship was statistically significant.

CONCLUSIONS

In conclusion, the implementation of video calls between mothers and preterm infants in NICUs had a healing effect on the physiological parameters of preterm infants and increased mother-infant bonding.

The effect of early postnatal auditory stimulation on outcomes in preterm infants

Preterm infants are deprived of in utero sensory stimulation during the third trimester, an important period of central nervous system development. As a result, maturational trajectories are often reduced in infants born preterm. One such system affected is the brain including the auditory and respiratory control pathways. During normal pregnancy the intrauterine environment attenuates external auditory stimuli while exposing the fetus to filtered maternal voice, intra-abdominal sounds, and external stimuli. In contrast, during the third trimester of development, preterm infants are exposed to a vastly different soundscape including non-attenuated auditory sounds and a lack of womb related stimuli, both of which may affect postnatal brain maturation. Therefore, fostering a nurturing postnatal auditory environment during hospitalization may have a significant impact on related outcomes of preterm infants. Studies using a range of postnatal auditory stimulations have suggested that exposure to sounds or lack thereof can have a significant impact on outcomes. However, studies are inconsistent with sound levels, duration of exposure to auditory stimuli, and the gestational age at which infants are exposed. IMPACT: Auditory stimulation can provide a low cost and low risk intervention to stabilize respiration, improve neuronal maturation and reduce long-term sequelae in preterm infants. The potential benefits of auditory stimulation are dependent on the type of sound, the duration of exposure and age at time of exposure. Future studies should focus on the optimal type and duration of sound exposure and postnatal developmental window to improve outcomes.

Investigating Relations between the NICU Speech Environment and Weight Gain in Infants Born Very Preterm

OBJECTIVE

Children born preterm, especially those born very preterm (<32 weeks of gestational age [GA]) are at risk for poor growth and adverse neurodevelopmental outcomes. Adverse growth and neurodevelopmental outcomes in preterm children have been attributed, in part, to the aversive sounds and relative speech paucity of the neonatal intensive care unit (NICU). Experimental studies that directly expose preterm infants to speech sounds in the NICU find significant improvements in health factors relevant to neurodevelopment. Few studies have examined whether natural variations in the speech environment of the NICU are related to short-term health outcomes in preterm infants. Such data are important for optimizing the sound environment of the NICU. Our objective was to examine relations between the NICU speech environment and the rate of weight gain during hospitalization.

STUDY DESIGN

Participants were infants born very preterm (n = 20). The speech environment of each infant was assessed at 32 to 36 weeks of postmenstrual age using an automatic speech-counting device. Average rates of weight gain (g/kg/d) were ascertained over the same period. Calories were derived from charted intake (kcals/kg/d). Linear regressions examined caloric intake and speech counts as predictors of infant weight gain.

RESULTS

Infant weight gain was significantly predicted by caloric intake and speech exposure, each uniquely accounting for approximately 27% variance (total R 2 = 60.2%; p < 0.001). Speech counts were uncorrelated with rates of family visitation, time in incubator, or health acuity.

CONCLUSION

While future research should establish causality and direction of effects, enhancing speech exposure in the NICU may be beneficial for physical growth. NICU care plans should consider opportunities to increase speech exposure.

KEY POINTS

· Preterm infants who experienced greater amounts of speech in the NICU gained significantly more weight than preterm infants who were exposed to lower amounts of speech during the same developmental period (32-36 weeks of postmenstrual age).. · Caloric intake and speech counts accounted for almost 60% of variance in infant weight gain between 32 and 36 weeks of postmenstrual age.. · Speech counts were not significantly correlated with family visitation, how long infants resided in incubators, or health acuity.. · Findings suggest that the NICU speech environment may play an important role in the physical health of preterm infants; however, more studies are needed to determine the directionality of the observed associations..

The effect of the simulated intrauterine sound on behavioral and physiological indices of pain during capillary blood sampling for screening preterm infants: a randomized clinical trial study

INTRODUCTION

Due to medical procedures, preterm infants are at high risk for side effects of pain. In this regard, heel lancing for capillary blood sampling is a common painful procedure. The present study was conducted to assess the effectiveness of a simulated intrauterine sound on behavioral and physiological indices of pain due to heel-prick blood sampling in preterm infants.

METHODS

A double‑blind randomized clinical trial (RCT) was conducted. The data were collected from September 23 to December 22, 2019. We measured the effect of a simulated intrauterine sound on changes in the behavioral and physiological parameters of pain (heart rate, SPO2) caused by heel lance that was measured 5 min before the intervention, during the sampling, and 5 min after the procedure. We measured behavioral pain by video recording the infants' faces and then the scoring neonatal infant pain scale (NIPS). Heart rate and SPO2 were measured using a pulse oximeter device. The data were analyzed using analysis of variance (ANOVA) and independent t‑test in SPSS software version 20.0.

RESULTS

Eighty infants were randomized (40 in each group). Mean scores NIPS during and after intervention were in the intervention group (3.55 ± 0.84, 95% CI: 3.30-3.80(, and (1.15 ± 0.84, 95%: 0.95-1.35) and in the control group (5.57 ± 0.95, 95% CI:5.30-5.85) and (3.00 ± 0.98) respectively. There were significant differences in scores of NIPS between the two study groups during (p < 0.001) and five min after heel lancing (p < 0.001). Mean scores of heart rate in the three phases of before, during, and five min after the intervention were respectively in the intervention group (127.57 ± 4.45, 95% CI:126.27-128.99), (131.07 ± 6.54, 95% CI:129.20-133.22), (128.45 ± 5.15, 95% CI:127.02-130.07) and in the control group (128.67 ± 4.57, 95% CI:127.32-130.07), (136.07 ± 7.24, 95% CI:133.90-138.37), and (132.42 ± 6.47, 95% CI:130.37-134.49). There were significant differences in heart rate between the intervention and the control group during (p = 0.002) and five min after the heel lance (p = 0.003). Mean scores of SPO2 in the three phases of baseline, during, and five min after the intervention were respectively in the intervention group (96.72 ± 0.93, 95% CI:96.42-97.00), (91.47 ± 1.46, 95% CI:91.05-91.92), (94.17 ± 1.03, 95% CI:93.22-94.00) and in the control group (96.6 ± 0.84, 95% CI:96.35-96.85), (91.5 ± 1.24, 95% CI:91.12-91.87), and (93.60 ± 1.27, 95% CI:93.85-94.50).

CONCLUSION

This study showed that the simulated intrauterine sound reduces the behavioral pain and heart rate in the intervention group during and after heel lance. These results suggest using the method during the painful heel lancing to reduce pain parameters in preterm infants.

Linking vestibular, tactile, and somatosensory rhythm perception to language development in infancy

First experiences with rhythm occur in the womb, with different rhythmic sources being available to the human fetus. Among sensory modalities, vestibular, tactile, and somatosensory perception plays a crucial role in early processing. However, a limited number of studies so far have specifically focused on VTS rhythms in language development. The present work investigated VTS rhythmic abilities and their role in language acquisition through two experiments with 45 infants (21 females, sex assigned at birth; M age = 661.6 days, SD = 192.6) with middle/high socioeconomic status. Specifically, 37 infants from the original sample completed Experiment 1, assessing VTS rhythmic abilities through a vibrotactile tool for music perception. In Experiment 2, linguistic abilities were evaluated in 40 participants from the same cohort, specifically testing phonological and prosodic processing. Discrimination abilities for rhythmic and linguistic stimuli were inferred from changes in pupil diameter to contingent visual stimuli over time, through a Tobii X-60 eye-tracker. The predictive effect of VTS rhythmic abilities on linguistic processing and the developmental changes occurring across ages were explored in the 32 infants who completed both Experiments 1 and 2 by means of generalized, additive and linear, mixed-effect models. Results are discussed in terms of cross-sensory (i.e., haptic to hearing) and cross-domain (i.e., music to language) effects of rhythm on language acquisition, with implications for typical and atypical development.

Preventing Excessive Noise Exposure in Infants, Children, and Adolescents

Noise exposure is a major cause of hearing loss in adults. Yet, noise affects people of all ages, and noise-induced hearing loss is also a problem for young people. Sensorineural hearing loss caused by noise and other toxic exposures is usually irreversible. Environmental noise, such as traffic noise, can affect learning, physiologic parameters, and quality of life. Children and adolescents have unique vulnerabilities to noise. Children may be exposed beginning in NICUs and well-baby nurseries, at home, at school, in their neighborhoods, and in recreational settings. Personal listening devices are increasingly used, even by small children. Infants and young children cannot remove themselves from noisy situations and must rely on adults to do so, children may not recognize hazardous noise exposures, and teenagers generally do not understand the consequences of high exposure to music from personal listening devices or attending concerts and dances. Environmental noise exposure has disproportionate effects on underserved communities. In this report and the accompanying policy statement, common sources of noise and effects on hearing at different life stages are reviewed. Noise-abatement interventions in various settings are discussed. Because noise exposure often starts in infancy and its effects result mainly from cumulative exposure to loud noise over long periods of time, more attention is needed to its presence in everyday activities starting early in life. Listening to music and attending dances, concerts, and celebratory and other events are sources of joy, pleasure, and relaxation for many people. These situations, however, often result in potentially harmful noise exposures. Pediatricians can potentially lessen exposures, including promotion of safer listening, by raising awareness in parents, children, and teenagers. Noise exposure is underrecognized as a serious public health issue in the United States, with exposure limits enforceable only in workplaces and not for the general public, including children and adolescents. Greater awareness of noise hazards is needed at a societal level.

Musical and vocal interventions to improve neurodevelopmental outcomes for preterm infants

BACKGROUND

Preterm birth interferes with brain maturation, and subsequent clinical events and interventions may have additional deleterious effects. Music as therapy is offered increasingly in neonatal intensive care units aiming to improve health outcomes and quality of life for both preterm infants and the well-being of their parents. Systematic reviews of mixed methodological quality have demonstrated ambiguous results for the efficacy of various types of auditory stimulation of preterm infants. A more comprehensive and rigorous systematic review is needed to address controversies arising from apparently conflicting studies and reviews.

OBJECTIVES

We assessed the overall efficacy of music and vocal interventions for physiological and neurodevelopmental outcomes in preterm infants (< 37 weeks' gestation) compared to standard care. In addition, we aimed to determine specific effects of various interventions for physiological, anthropometric, social-emotional, neurodevelopmental short- and long-term outcomes in the infants, parental well-being, and bonding.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, PsycINFO, Web of Science, RILM Abstracts, and ERIC in November 2021; and Proquest Dissertations in February 2019. We searched the reference lists of related systematic reviews, and of studies selected for inclusion and clinical trial registries.

SELECTION CRITERIA

We included parallel, and cluster-randomised controlled trials with preterm infants < 37 weeks` gestation during hospitalisation, and parents when they were involved in the intervention. Interventions were any music or vocal stimulation provided live or via a recording by a music therapist, a parent, or a healthcare professional compared to standard care. The intervention duration was greater than five minutes and needed to occur more than three times.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data. We analysed the treatment effects of the individual trials using RevMan Web using a fixed-effects model to combine the data. Where possible, we presented results in meta-analyses using mean differences with 95% CI. We performed heterogeneity tests. When the I2 statistic was higher than 50%, we assessed the source of the heterogeneity by sensitivity and subgroup analyses. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 25 trials recruiting 1532 infants and 691 parents (21 parallel-group RCTs, four cross-over RCTs). The infants gestational age at birth varied from 23 to 36 weeks, taking place in NICUs (level 1 to 3) around the world. Within the trials, the intervention varied widely in type, delivery, frequency, and duration. Music and voice were mainly characterised by calm, soft, musical parameters in lullaby style, often integrating the sung mother's voice live or recorded, defined as music therapy or music medicine. The general risk of bias in the included studies varied from low to high risk of bias. Music and vocal interventions compared to standard care Music/vocal interventions do not increase oxygen saturation in the infants during the intervention (mean difference (MD) 0.13, 95% CI -0.33 to 0.59; P = 0.59; 958 infants, 10 studies; high-certainty evidence). Music and voice probably do not increase oxygen saturation post-intervention either (MD 0.63, 95% CI -0.01 to 1.26; P = 0.05; 800 infants, 7 studies; moderate-certainty evidence). The intervention may not increase infant development (Bayley Scales of Infant and Toddler Development (BSID)) with the cognitive composition score (MD 0.35, 95% CI -4.85 to 5.55; P = 0.90; 69 infants, 2 studies; low-certainty evidence); the motor composition score (MD -0.17, 95% CI -5.45 to 5.11; P = 0.95; 69 infants, 2 studies; low-certainty evidence); and the language composition score (MD 0.38, 95% CI -5.45 to 6.21; P = 0.90; 69 infants, 2 studies; low-certainty evidence). Music therapy may not reduce parental state-trait anxiety (MD -1.12, 95% CI -3.20 to 0.96; P = 0.29; 97 parents, 4 studies; low-certainty evidence). The intervention probably does not reduce respiratory rate during the intervention (MD 0.42, 95% CI -1.05 to 1.90; P = 0.57; 750 infants; 7 studies; moderate-certainty evidence) and post-intervention (MD 0.51, 95% CI -1.57 to 2.58; P = 0.63; 636 infants, 5 studies; moderate-certainty evidence). However, music/vocal interventions probably reduce heart rates in preterm infants during the intervention (MD -1.38, 95% CI -2.63 to -0.12; P = 0.03; 1014 infants; 11 studies; moderate-certainty evidence). This beneficial effect was even stronger after the intervention. Music/vocal interventions reduce heart rate post-intervention (MD -3.80, 95% CI -5.05 to -2.55; P < 0.00001; 903 infants, 9 studies; high-certainty evidence) with wide CIs ranging from medium to large beneficial effects. Music therapy may not reduce postnatal depression (MD 0.50, 95% CI -1.80 to 2.81; P = 0.67; 67 participants; 2 studies; low-certainty evidence). The evidence is very uncertain about the effect of music therapy on parental state anxiety (MD -0.15, 95% CI -2.72 to 2.41; P = 0.91; 87 parents, 3 studies; very low-certainty evidence). We are uncertain about any further effects regarding all other secondary short- and long-term outcomes on the infants, parental well-being, and bonding/attachment. Two studies evaluated adverse effects as an explicit outcome of interest and reported no adverse effects from music and voice.

AUTHORS' CONCLUSIONS

Music/vocal interventions do not increase oxygen saturation during and probably not after the intervention compared to standard care. The evidence suggests that music and voice do not increase infant development (BSID) or reduce parental state-trait anxiety. The intervention probably does not reduce respiratory rate in preterm infants. However, music/vocal interventions probably reduce heart rates in preterm infants during the intervention, and this beneficial effect is even stronger after the intervention, demonstrating that music/vocal interventions reduce heart rates in preterm infants post-intervention. We found no reports of adverse effects from music and voice. Due to low-certainty evidence for all other outcomes, we could not draw any further conclusions regarding overall efficacy nor the possible impact of different intervention types, frequencies, or durations. Further research with more power, fewer risks of bias, and more sensitive and clinically relevant outcomes are needed.

Maternal voice reduces procedural pain in neonates: A meta-analysis of randomized controlled trials

BACKGROUND

Procedural pain management is a very important part in the clinical care of neonates. We aimed to conduct a meta-analysis to evaluate the effects of maternal voice on neonatal procedural pain, to provide insights to the clinical pain care of neonates.

METHODS

Two researchers independently searched PubMed, EMBASE, The Cochrane Library, CINAHL, Web of Science, China Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang and Weipu Database for randomized controlled trials (RCTs) involving the effects of maternal voice on the procedural pain of neonates up to October 25, 2022. Two investigators screened the literature based on the inclusion and exclusion criteria and evaluated the methodological quality of the inclusion study. RevMan 5.3 software was used for the meta-analysis.

RESULTS

A total of 8 RCTs with a total of 584 neonates were included. Our meta-analysis indicated that maternal voice reduces the pain score (SMD = -0.60, 95% CI: -0.81 to -0.39) and heart rate (SMD = -0.81, 95% CI: -1.44 to -0.18) and increases the comfort level (SMD = -0.47, 95% CI: -0.83 to -0.11) and blood oxygen saturation (SMD = 0.70, 95% CI: 0.03-1.38) during procedure (all P < .05). Moreover, maternal voice reduces the pain score (SMD = -0.58, 95% CI: -0.88 to -0.28) and heart rate (SMD = -0.44, 95% CI: -0.75 to -0.12) and increases the blood oxygen saturation (SMD = 0.41, 95% CI: 0.00 to -0.82) after procedure (all P < .05). No publication biases were detected by the funnel plots and Egger tests (all P > .05).

CONCLUSION

Maternal voice is beneficial to reduce procedural pain and improve the physiological indicators in neonates. It is still necessary to conduct high-quality, large sample studies in the future to further elucidate the effect of maternal voice on neonatal pain care.

Ideal Mode of Auditory Stimulation in Preterm Neonates in Neonatal Intensive Care Unit: A Systematic Review

The objective of this review was to find out the best mode of auditory stimulation for preterm neonates admitted to the neonatal intensive care unit. We also aimed to find out the different effects of different types of auditory stimulation in these neonates. Advanced neonatal care and technological advances in neonatal intensive care units have led to increased survival of preterm-born neonates, but this in turn leads to increased incidences of disabilities like cerebral palsy, visual impairment, delayed social development, etc. Early intervention is provided to facilitate further development and prevent delays in all domains. Auditory stimulation is proven to benefit these neonates to stabilize their vitals and improve their auditory performance in later life. Different modes of auditory stimulation have been studied worldwide, but none of the studies has presented the ideal mode of auditory stimulation for these preterm neonates. In this review, we have discussed the effects produced by different types of auditory stimulation and compared their pros and cons. For conducting a systematic review, a search strategy adopted by MEDLINE is used. A total of 78 articles published between 2012 and 2017, on the effects of auditory stimulation on preterm infants' performance were reviewed. Out of that, eight studies that met the inclusion criteria and focused on short-term and long-term effects were included in this systematic review. Search terms included preterm neonates, auditory stimulation, and early intervention. Randomized controlled trials and cohort studies were included. Auditory stimulation by maternal sound provides physiological and autonomic stability, but the behavioral states of preterm neonates improved with auditory stimulation by music therapy with lullabies. Maternal singing during kangaroo care may be recommended for providing physiological stability.

Effect of maternal voice on proportion of oral feeding in preterm infants

OBJECTIVE

To determine the impact of maternal voice exposure on oral feeding in preterm infants.

STUDY DESIGN

Prospective, unblinded, 2-center intervention study of infants born 28 0/7-34 6/7 weeks gestation. Infants were exposed twice daily to maternal voice for 20 min before attempting oral feeding. Feedings were divided into groups consisting of Baseline, Intervention, and Follow-up feeds. The study was registered at clinicaltrials.gov (NCT05181020).

RESULT

29/37 (78%) mother-infant dyads consented for the study. 25 infants with 2051 feedings were included. Compared to the preceding Baseline, Intervention feeds were associated with an adjusted 7.1 percentage-point increase in oral intake (p = 0.036) and in post-hoc analysis a 71% increased likelihood of having the highest feeding readiness score (p = 0.003).

CONCLUSION

Exposure to maternal voice prior to enteral feeding is feasible and was associated with significantly improved oral feeding proportions in preterm infants.

CLINICAL TRIAL REGISTRY

clinicaltrials.gov (NCT05181020).

Sensory stimulation for apnoea mitigation in preterm infants

Apnoea, a pause in respiration, is ubiquitous in preterm infants and are often associated with physiological instability, which may lead to longer-term adverse neurodevelopmental consequences. Despite current therapies aimed at reducing the apnoea burden, preterm infants continue to exhibit apnoeic events throughout their hospital admission. Bedside staff are frequently required to manually intervene with different forms of stimuli, with the aim of re-establishing respiratory cadence and minimizing the physiological impact of each apnoeic event. Such a reactive approach makes apnoea and its associated adverse consequences inevitable and places a heavy reliance on human intervention. Different approaches to improving apnoea management in preterm infants have been investigated, including the use of various sensory stimuli. Despite studies reporting sensory stimuli of various forms to have potential in reducing apnoea frequency, non-invasive intermittent positive pressure ventilation is the only automated stimulus currently used in the clinical setting for infants with persistent apnoeic events. We find that the development of automated closed-looped sensory stimulation systems for apnoea mitigation in preterm infants receiving non-invasive respiratory support is warranted, including the possibility of stimulation being applied preventatively, and in a multi-modal form. IMPACT: This review examines the effects of various forms of sensory stimulation on apnoea mitigation in preterm infants, namely localized tactile, generalized kinesthetic, airway pressure, auditory, and olfactory stimulations. Amongst the 31 studies reviewed, each form of sensory stimulation showed some positive effects, although the findings were not definitive and comparative studies were lacking. We find that the development of automated closed-loop sensory stimulation systems for apnoea mitigation is warranted, including the possibility of stimulation being applied preventatively, and in a multi-modal form.

Sensory-based interventions in the NICU: systematic review of effects on preterm brain development

BACKGROUND

Infants born preterm are known to be at risk for abnormal brain development and adverse neurobehavioral outcomes. To improve early neurodevelopment, several non-pharmacological interventions have been developed and implemented in the neonatal intensive care unit (NICU). Sensory-based interventions seem to improve short-term neurodevelopmental outcomes in the inherently stressful NICU environment. However, how this type of intervention affects brain development in the preterm population remains unclear.

METHODS

A systematic review of the literature was conducted for published studies in the past 20 years reporting the effects of early, non-pharmacological, sensory-based interventions on the neonatal brain after preterm birth.

RESULTS

Twelve randomized controlled trials (RCT) reporting short-term effects of auditory, tactile, and multisensory interventions were included after the screening of 1202 articles. Large heterogeneity was identified among studies in relation to both types of intervention and outcomes. Three areas of focus for sensory interventions were identified: auditory-based, tactile-based, and multisensory interventions.

CONCLUSIONS

Diversity in interventions and outcome measures challenges the possibility to perform an integrative synthesis of results and to translate these for evidence-based clinical practice. This review identifies gaps in the literature and methodological challenges for the implementation of RCTs of sensory interventions in the NICU.

IMPACT

This paper represents the first systematic review to investigate the effect of non-pharmacological, sensory-based interventions in the NICU on neonatal brain development. Although reviewed RCTs present evidence on the impact of such interventions on the neonatal brain following preterm birth, it is not yet possible to formulate clear guidelines for clinical practice. This review integrates existing literature on the effect of sensory-based interventions on the brain after preterm birth and identifies methodological challenges for the conduction of high-quality RCTs.

The Role of Music Therapy with Infants with Perinatal Brain Injury

Perinatal brain injury occurs in 5.14/1000 live births in England. A significant proportion of these injuries result from hypoxic ischaemic encephalopathy (HIE) in term infants and intracranial haemorrhage (IVH) or periventricular leukomalacia (PVL) in preterm infants. Standardised care necessitates minimal handling from parents and professionals to reduce the progression of injury. This can potentially increase parental stress through the physical inability to bond with their baby. Recent research highlights the ability of music therapy (MT) to empower parental bonding without handling, through sharing culturally informed personal music with their infant. This review therefore aimed to systematically evaluate the use of MT with infants diagnosed with perinatal brain injury in a neonatal intensive care unit (NICU). Search terms were combined into three categories (audio stimulation (MT), population (neonates) and condition (brain injury), and eight electronic databases were used to identify relevant studies following PRISMA guidelines. Eleven studies using music or vocal stimulation with infants diagnosed with perinatal brain injury were identified and quality assessed using Cochrane ROB2, the ROBINSI Tool and the Newcastle Ottawa Scale. Studies used either voice as live (n = 6) or pre-recorded (n = 3) interventions or pre-recorded instrumental music (n = 2). Studies had two primary areas of focus: developmental outcomes and physiological effects. Results suggested the use of music interventions led to a reduction of infants' pain scores during procedures and cardiorespiratory events, improved feeding ability (increase oral feeding rate, volume intake and feeds per day) and resulted in larger amygdala volumes than control groups. Additionally, MT intervention on the unit supported long-term hospitalised infants in the acquisition of developmental milestones. Vocal soothing was perceived to be an accessible intervention for parents. However, infants with PVL showed signs of stress in complex interventions, which also potentially resulted in an increase in maternal anxiety in one study. MT with infants diagnosed with perinatal brain injury can have positive effects on infants' behavioural and neurological parameters and support parental involvement in their infants' developmental care. Further feasibility studies are required using MT to determine appropriate outcome measures for infants and the support required for parents to allow future comparison in large-scale randomised control trials.

A Dynamical, Radically Embodied, and Ecological Theory of Rhythm Development

Musical rhythm abilities-the perception of and coordinated action to the rhythmic structure of music-undergo remarkable change over human development. In the current paper, we introduce a theoretical framework for modeling the development of musical rhythm. The framework, based on Neural Resonance Theory (NRT), explains rhythm development in terms of resonance and attunement, which are formalized using a general theory that includes non-linear resonance and Hebbian plasticity. First, we review the developmental literature on musical rhythm, highlighting several developmental processes related to rhythm perception and action. Next, we offer an exposition of Neural Resonance Theory and argue that elements of the theory are consistent with dynamical, radically embodied (i.e., non-representational) and ecological approaches to cognition and development. We then discuss how dynamical models, implemented as self-organizing networks of neural oscillations with Hebbian plasticity, predict key features of music development. We conclude by illustrating how the notions of dynamical embodiment, resonance, and attunement provide a conceptual language for characterizing musical rhythm development, and, when formalized in physiologically informed dynamical models, provide a theoretical framework for generating testable empirical predictions about musical rhythm development, such as the kinds of native and non-native rhythmic structures infants and children can learn, steady-state evoked potentials to native and non-native musical rhythms, and the effects of short-term (e.g., infant bouncing, infant music classes), long-term (e.g., perceptual narrowing to musical rhythm), and very-long term (e.g., music enculturation, musical training) learning on music perception-action.

RETRACTED: Effect of White Noise and Lullabies on Pain and Vital Signs in Invasive Interventions Applied to Premature Babies

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The editors have decided to retract the article based on the lack of ethical standard care interventions that should have been administered to the control group during planned blood collection. That standard of care includes known, evidence-based interventions such as massage, kangaroo care, listening to music, non-nutritive sucking/pacifier, and wrapping.

Effect of Recorded Maternal Voice on Emergence Delirium in Children Under General Anesthesia: A Randomized Controlled Trial

ABSTRACT

To determine the effect of recorded maternal voice on emergence delirium (ED) in children under general anesthesia, a three-group randomized trial was conducted. A total of 102 children were randomly assigned to mother recording group (n = 34), stranger recording group (n = 34), and control group (n = 34). All subjects were assessed for ED with the Pediatric Anesthesia Emergence Delirium Scale; pain with the Face, Legs, Activity, Cry, and Consolability Scale; and various recovery durations and hemodynamic parameters at six time points. One-way analysis of variance showed that the ED score was significantly lower in the mother recording group (F = 18.520, p = 0.000), and statistical significance was observed in the duration of eye opening (p = 0.001) and tracheal extubation (p = 0.002). Generalized estimating equations observed interaction effects on heart rate and blood pressure (both p = 0.000). Mothers' voice might help reduce ED in children under general anesthesia.

Parental Book-Reading to Preterm Born Infants in NICU: The Effects on Language Development in the First Two Years

Background: After preterm birth, infants are at high risk for delays in language development. A promising intervention to reduce this risk is represented by the exposure to parental voices through book-reading in Neonatal Intensive Care Units (NICU). This study investigated the possible advantages of book-reading to preterm neonates during their NICU stay on their subsequent language development. Methods: 100 families of preterm infants were recruited. The parents of 55 preterm infants (Reading Group) received a colored picture-book on NICU admission and were supported to read to their neonate as often as possible and to continue after hospital discharge. Forty-five infants (Control Group) were recruited before the beginning of the intervention. Infant language development was assessed with the Hearing and Language quotients of the Griffith Mental Development Scale at the corrected ages of 3, 6, 9, 12, 18 and 24 months. Results: Regardless of group membership, Hearing and Language mean quotients decreased between 9 and 18 months; nevertheless, this decrease was considerably reduced in the Reading group, compared to the Control Group. Conclusions: Reading in NICUs represents a suitable intervention that could positively influence language development and parent-infant relationships in preterm children. The study findings support its implementation as a preventive measure.

Repeated Parental Singing During Kangaroo Care Improved Neural Processing of Speech Sound Changes in Preterm Infants at Term Age

Preterm birth carries a risk for adverse neurodevelopment. Cognitive dysfunctions, such as language disorders may manifest as atypical sound discrimination already in early infancy. As infant-directed singing has been shown to enhance language acquisition in infants, we examined whether parental singing during skin-to-skin care (kangaroo care) improves speech sound discrimination in preterm infants. Forty-five preterm infants born between 26 and 33 gestational weeks (GW) and their parents participated in this cluster-randomized controlled trial (ClinicalTrials ID IRB00003181SK). In both groups, parents conducted kangaroo care during 33-40 GW. In the singing intervention group (n = 24), a certified music therapist guided parents to sing or hum during daily kangaroo care. In the control group (n = 21), parents conducted standard kangaroo care and were not instructed to use their voices. Parents in both groups reported the duration of daily intervention. Auditory event-related potentials were recorded with electroencephalogram at term age using a multi-feature paradigm consisting of phonetic and emotional speech sound changes and a one-deviant oddball paradigm with pure tones. In the multi-feature paradigm, prominent mismatch responses (MMR) were elicited to the emotional sounds and many of the phonetic deviants in the singing intervention group and in the control group to some of the emotional and phonetic deviants. A group difference was found as the MMRs were larger in the singing intervention group, mainly due to larger MMRs being elicited to the emotional sounds, especially in females. The overall duration of the singing intervention (range 15-63 days) was positively associated with the MMR amplitudes for both phonetic and emotional stimuli in both sexes, unlike the daily singing time (range 8-120 min/day). In the oddball paradigm, MMRs for the non-speech sounds were elicited in both groups and no group differences nor connections between the singing time and the response amplitudes were found. These results imply that repeated parental singing during kangaroo care improved auditory discrimination of phonetic and emotional speech sounds in preterm infants at term age. Regular singing routines can be recommended for parents to promote the development of the auditory system and auditory processing of speech sounds in preterm infants.

The Importance of Rhythmic Stimulation for Preterm Infants in the NICU

The fetal environment provides the fetus with multiple potential sources of rhythmic stimulation that are not present in the NICU. Maternal breathing, heartbeats, walking, dancing, running, speaking, singing, etc., all bathe the fetus in an environment of varied rhythmic stimuli: vestibular, somatosensory, tactile, and auditory. In contrast, the NICU environment does not offer the same proportion of rhythmic stimulation. After analyzing the lack of rhythmic stimulation in the NICU, this review highlights the different proposals for vestibular and/or auditory rhythmic stimulation offered to preterm infants alone and with their parents. The focus is on the beneficial effects of auditory and vestibular stimulation involving both partners of the mother-infant dyad. A preliminary study on the influence of a skin-to-skin lullaby on the stability of maternal behavior and on the tonic emotional manifestations of the preterm infant is presented as an example. The review concludes with the importance of introducing rhythmic stimulations in the NICU.

Listening to Mom in the NICU: effects of increased maternal speech exposure on language outcomes and white matter development in infants born very preterm

BACKGROUND

Infants born very preterm (< 32 weeks gestational age (GA)) are at risk for developmental language delays. Poor language outcomes in children born preterm have been linked to neurobiological factors, including impaired development of the brain's structural connectivity (white matter), and environmental factors, including decreased exposure to maternal speech in the neonatal intensive care unit (NICU). Interventions that enhance preterm infants' exposure to maternal speech show promise as potential strategies for improving short-term health outcomes. Intervention studies have yet to establish whether increased exposure to maternal speech in the NICU offers benefits beyond the newborn period for brain and language outcomes.

METHODS

This randomized controlled trial assesses the long-term effects of increased maternal speech exposure on structural connectivity at 12 months of age (age adjusted for prematurity (AA)) and language outcomes between 12 and 18 months of age AA. Study participants (N = 42) will include infants born very preterm (24-31 weeks 6/7 days GA). Newborns are randomly assigned to the treatment (n = 21) or standard medical care (n = 21) group. Treatment consists of increased maternal speech exposure, accomplished by playing audio recordings of each baby's own mother reading a children's book via an iPod placed in their crib/incubator. Infants in the control group have the identical iPod setup but are not played recordings. The primary outcome will be measures of expressive and receptive language skills, obtained from a parent questionnaire collected at 12-18 months AA. The secondary outcome will be measures of white matter development, including the mean diffusivity and fractional anisotropy derived from diffusion magnetic resonance imaging scans performed at around 36 weeks postmenstrual age during the infants' routine brain imaging session before hospital discharge and 12 months AA.

DISCUSSION

The proposed study is expected to establish the potential impact of increased maternal speech exposure on long-term language outcomes and white matter development in infants born very preterm. If successful, the findings of this study may help to guide NICU clinical practice for promoting language and brain development. This clinical trial has the potential to advance theoretical understanding of how early language exposure directly changes brain structure for later language learning.

TRIAL REGISTRATION

NIH Clinical Trials (ClinicalTrials.gov) NCT04193579 . Retrospectively registered on 10 December 2019.

The effects of kangaroo mother care and music listening on physiological parameters, oxygen saturation, crying, awake state and sleep in infants in NICU

OBJECTIVE

Kangaroo mother care and musical stimulation are recommended nursing interventions in the NICU. However, there is little research on the combination of kangaroo care with musical stimulation and their relationship with the health condition of infants. The aim of the study was to compare the parameters of the physiological state and behavior of infants during kangaroo mother care as well as kangaroo mother care and musical stimulation.

STUDY DESIGN

The study included 100 infants, with corrected gestational ages of 35 weeks, with an average body weight of 2704 g. During kangaroo care the child was supported by their parent, then musical stimulation was added to kangaroo care. Measurements were made in an incubator after the 1st and the 15th minute of each intervention.

RESULTS

Neonatal parameters differed in the incubator and during each intervention. During kangaroo care and kangaroo care and musical stimulation, heart rate (p < .0001), respiration rate (p < .0001), crying (p < .0001) and awake state (p < .0001) decreased, oxygen saturation levels (p < .0001) and the number of children who fell asleep (p < .0001) increased. During kangaroo care and musical stimulation significantly fewer children were awake (p = .0003) and more fell asleep (p < .0001) than after kangaroo care alone (p < .0001).

CONCLUSIONS

This study suggests that kangaroo care and kangaroo care and musical stimulation can be used to stabilize the physiological functions of infants. Kangaroo care and musical stimulation can be one of the most effective nursing interventions in the neonatal intensive care unit for the care of infants.

Assessing speech exposure in the NICU: Implications for speech enrichment for preterm infants

OBJECTIVE

Quantify NICU speech exposure over multiple days in relation to NICU care practices.

METHODS

Continuous measures of speech exposure were obtained for preterm infants (n = 21; 12 M) born <34 weeks gestational age in incubators (n = 12) or open cribs (n = 9) for 5-14 days. Periods of care (routine, developmental) and delivery source (family, medical staff, cuddler) were determined through chart review.

RESULTS

Infants spent 13% of their time in Care, with >75% of care time reflecting developmental care. Speech counts were higher during care than no care, for mature vs. immature infants, and for infants in open cribs vs. incubators. Family participation in care ranged widely, with the highest speech counts occurring during periods of intentional voice exposure.

CONCLUSIONS

Care activities represent a small portion of NICU experiences. Speech exposure during Developmental Care, especially with intentional voice exposure, may be an important source of stimulation. Implications for care practices are discussed.

Predictors of Parental Presence in the Neonatal Intensive Care Unit

BACKGROUND

Parental presence in the neonatal intensive care unit (NICU) may affect preterm infants' developmental outcomes. However, few studies have described predictors of parental presence in the NICU.

PURPOSE

To identify sociodemographic, clinical, environmental, and maternal psychological factors that predict parent presence in the NICU.

METHODS

Using a prospective cohort design, 66 preterm infants between 32 and 40 weeks' corrected gestational age were recruited at 2 level III NICUs in the United States. Data for length of parental presence were collected for 48 consecutive hours from daily visitation logs and medical records. A general linear model was estimated to identify significant predictors of parental presence.

RESULTS

Parental presence varied considerably, with a mean percentage of visitation time of 32.40%. The number of children at home (P = .003), presence of neurological comorbidity (P < .001), room type (P < .001), surgical history (P < .001), and perceived stressfulness of the NICU (P = .03) each had large main effects on parental presence, and room type and surgical history (P = .004) had a large interaction effect on parental presence. These predictors accounted for 65.8% of the variance in parental presence.

IMPLICATIONS FOR RESEARCH

Future research aimed at understanding predictors of parent presence is essential for developing interventions and designing NICUs that support parental presence.

IMPLICATIONS FOR PRACTICE

Understanding factors that contribute to parental presence may help healthcare providers identify infants at risk for low parental presence and thus be able to provide greater support to these infants and their families. As a result, this may help improve outcomes and attachment.

Neonatal intensive care unit incubators reduce language and noise levels more than the womb

OBJECTIVE

To assess the sound reducing characteristics of modern incubators in the neonatal intensive care unit (NICU) and to better characterize auditory and language exposures for NICU infants.

STUDY DESIGN

Sound frequency spectral analysis was conducted on language and noise audio acquired simultaneously inside and outside incubators located in the NICU.

RESULTS

Sound transmission into the incubators was nonuniform. Very low-frequency sounds (<100 Hz) were unattenuated or even slightly amplified inside the incubators. Maximal reduction was observed for low-to-mid frequencies (300-600 Hz) and high frequencies (>2000 Hz), which convey important language information.

CONCLUSIONS

Sound reductions observed across NICU incubator walls are more severe than those reported for sound transmission into the intrauterine environment, particularly for midrange frequencies that are important for language. Although incubator walls may serve as a protection against noxious noise levels, these findings reveal a potentially detrimental effect on language exposure for infants inside a NICU incubator.

Early vocal contact and music in the NICU: new insights into preventive interventions

It is now clearly established that the environment and the sensory stimuli, particularly during the perinatal period, have an impact on infant's development. During the last trimester of gestation, activity-dependent plasticity shapes the fetal brain, and prematurity has been shown to alter the typical developmental trajectories. In this delicate period, preventive interventions aiming at modulating these developmental trajectories through activity-inducing interventions are currently underway to be tested. The purpose of this review paper is to describe the potentialities of early vocal contact and music on the preterm infant's brain development, and their potential beneficial effect on early development. Scientific evidence supports a behavioral orientation of the newborn to organized sounds, such as those of voice and music, and recent neuroimaging studies further confirm full cerebral processing of music as multisensory stimuli. However, the impact of long-term effects of music exposure and early vocal contact on preterm infants' long-term neurodevelopment needs be further investigated. To conclude, it is necessary to establish the neuroscientific bases of the early perception and the long-term effects of music and early vocal contact on the premature newborns' development. Scientific projects are currently on the way to fill this gap in knowledge.

Integration of Different Sensory Interventions From Mother's Breast Milk for Preterm Infant Pain During Peripheral Venipuncture Procedures: A Prospective Randomized Controlled Trial

PURPOSE

To compare the effects of integrating mother's breast milk (BM) with three different combinations of sensory stimuli on preterm infant pain during peripheral venipuncture procedures.

DESIGN

A prospective, repeated-measures randomized controlled trial.

METHODS

Preterm infants (gestational age between 28 and 37 weeks, and in stable condition) needing venipuncture were recruited by convenience sampling (N = 140) and randomly assigned to four treatment conditions: (a) routine care (condition 1); (b) BM odor or taste (condition 2); (c) BM odor or taste + heartbeat sounds (HBs; condition 3), and (d) BM odor or taste + HBs + non-nutritive sucking (NNS; condition 4). Pain scores were assessed based on the Premature Infant Pain Profile-Revised (PIPP-R) over nine phases: baseline (phase 0, 5 min without stimuli before venipuncture), disinfecting (phase 1), during venipuncture (phase 2), and a 10-min recovery (phases 3-8).

FINDINGS

Infants who received BM odor or taste + HBs + NNS had significantly lower increases in pain scores from baseline compared with controls across phases 1 through 8. Infants treated with either condition 2 or 3 demonstrated significant reductions in mild pain during disinfecting and recovery phases, as compared with the controls. When condition 2 was used as the reference, there were no significant differences in pain scores between the infants receiving condition 3 across the nine phases, suggesting mothers' HBs have only mild analgesic effects on venipuncture pain.

CONCLUSIONS

Integration of mother's BM odor or taste, HBs, and tactile NNS should be considered as an intervention for alleviation of procedural pain for preterm infants.

CLINICAL RELEVANCE

Clinicians should incorporate the integrated sensory intervention into caregiving support for preterm infants undergoing short painful procedures.

Maternal Voice and Infant Sleep in the Neonatal Intensive Care Unit

BACKGROUND

Approximately 10% of US newborns require a NICU. We evaluated whether the NICU acoustic environment affects neonatal sleep and whether exposure to the mother's voice can modulate that impact.

METHODS

In a level IV NICU with single-infant rooms, 47 neonates underwent 12-hour polysomnography. Their mothers were recorded reading children's books. Continuous maternal voice playback was randomized to either the first or second 6 hours of the polysomnogram. Regression models were used to examine sleep-wake stages, entropy, EEG power, and the probability of awakening in response to ambient noise during and without voice playback.

RESULTS

After epochs with elevated noise, the probability was higher with (versus without) maternal voice exposure of neonates staying asleep (P = .009). However, the 20 neonates born at ≥35 weeks' gestation, in contrast to those born at 33 to 34 weeks, showed an age-related increase in percent time awake (R ² = 0.52; P < .001), a decrease in overall sleep (R ² = 0.52; P < .001), a reduction in rapid eye movement sleep bouts per hour (R ² = 0.35; P = .003), and an increase in sleep-wake entropy (R ² = 0.52; P < .001) all confined solely to the 6 hours of maternal voice exposure. These associations remained significant (P = .02 to P < .001) after adjustment for neurologic examination scores and ambient noise.

CONCLUSIONS

Hospitalized newborns born at ≥35 weeks' gestation but not at 33 to 34 weeks' gestation show increasing wakefulness in response to their mother's voice. However, exposure to the mother's voice during sleep may also help protect newborns from awakening after bursts of loud hospital noise.

What Are the Effects of the Maternal Voice on Preterm Infants in the NICU?

BACKGROUND/SIGNIFICANCE

Premature infants often experience extended stays in the neonatal intensive care unit (NICU) as opposed to home with parents. This prolonged separation creates a strain for both parents and infants, decreasing attachment and parental caregiving. One strategy to combat this shared stress is increasing parental participation, particularly through the use of their voices whether parents are present or not.

PURPOSE

This Evidence-Based Practice Brief column explores the connection between mother and child, specifically the effects of maternal voice on infant autonomic stability, weight gain, and behavioral states.

METHODS

A systematic search of CINAHL, PubMed, and PsycInfo was used to identify studies involving the use of maternal voice intervention with preterm infants in the NICU.

RESULTS

Fifteen studies were identified. Three intervention categories emerged: (1) live maternal speech, (2) recorded maternal speech (subcategories included whether intervention content was prescribed or not), and (3) recorded maternal speech that was combined with biological maternal sounds (heart rate). Within each category, studies were organized chronologically to reflect how knowledge has changed overtime.

IMPLICATIONS FOR PRACTICE

Maternal voice has physiological as well as behavioral and emotional effect on preterm infants. Several studies found that maternal voice increased autonomic stability improving (heart rate and respirations) as well as weight gain. No negative effects were identified. Given these findings, incorporating different types of maternal voice into routine care by the bedside nurse can assist the mother in feeling more involved in her infant's care without seemingly being a distraction or obstacle to providers.

IMPLICATIONS FOR RESEARCH

A major limitation for generalizability was sample size; more research is needed with larger sample sizes replicating interventions types to discern best outcomes.Video Abstract available at https://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?videoId=31&autoPlay=true.

Reducing toxic stress in the neonatal intensive care unit to improve infant outcomes

In 2011, the American Academy of Pediatrics (AAP) published a technical report on the lifelong effects of early toxic stress on human development, and included a new framework for promoting pediatric health: the Ecobiodevelopmental Framework for Early Childhood Policies and Programs. We believe that hospitalization is a specific form of toxic stress for the neonatal patient, and that toxic stress must be addressed by the nursing profession in order to substantially improve outcomes for the critically ill neonate. Approximately 4% of normal birthweight newborns and 85% of low birthweight newborns are hospitalized each year in the highly technological neonatal intensive care unit (NICU). Neonates are exposed to roughly 70 stressful procedures a day during hospitalization, which can permanently and negatively alter the infant's developing brain. Neurologic deficits can be partly attributed to the frequent, toxic, and cumulative exposure to stressors during NICU hospitalization. However, the AAP report does not provide specific action steps necessary to address toxic stress in the NICU and realize the new vision for pediatric health care outlined therein. Therefore, this paper applies the concepts and vision laid out in the AAP report to the care of the hospitalized neonate and provides action steps for true transformative change in neonatal intensive care. We review how the environment of the NICU is a significant source of toxic stress for hospitalized infants. We provide recommendations for caregiving practices that could significantly buffer the toxic stress experienced by hospitalized infants. We also identify areas of research inquiry that are needed to address gaps in nursing knowledge and to propel nursing science forward. Finally, we advocate for several public policies that are not fully addressed in the AAP technical report, but are vital to the health and development of all newborns.

Changes in autonomic regulation due to Kangaroo care remain unaffected by using a swaddling device

Aim

To investigate the effects of a swaddling device known as the Hugsy (Hugsy, Eindhoven, the Netherlands) towards improving autonomic regulation. This device can be used both in the incubator and during Kangaroo care to absorb parental scent and warmth. After Kangaroo care, these stimuli can continue to be experienced by infants, while in the incubator. Additionally, a pre‐recorded heartbeat sound can be played.

Method

Autonomic regulation was compared in preterm infants before, during and after Kangaroo care with and without the use of a swaddling device in a within‐subject study carried out in a level III neonatal intensive care unit. Descriptive statistics and effect sizes were calculated corresponding to changes in heart rate, respiratory rate, oxygen saturation, temperature and heart rate variability on intervention versus control days.

Results

In this study of 20 infants with a median (interquartile range) gestational age of 28.4 (27–29.9) weeks, Kangaroo care was associated with a decrease in heart rate, respiratory rate and heart rate variability on both intervention and control days. There were no differences between intervention and control days.

Conclusion

The use of an alternative swaddling device aimed at facilitating Kangaroo care did not enhance autonomic regulation, as measured by vital signs and heart rate variability.

[Clinical effect of maternal voice stimulation in alleviating procedural pain in hospitalized neonates]

OBJECTIVE

To study the clinical effect of maternal voice stimulation in alleviating procedural pain in neonates during heel blood collection.

METHODS

A total of 72 neonates who were admitted to the neonate intensive care unit were randomly divided into an intervention group (n=35) and a control group (n=37). Heel blood collection was performed by the routine method in the control group. The intervention group listened to their mothers' voice from 1 minute before heel blood collection to the end of the procedure. Pain score, incidence of crying, and vital signs were recorded before and after heel blood collection.

RESULTS

Compared with the control group, the heart rate was significantly reduced, the blood oxygen saturation significantly increased, the incidence of crying and the pain score were significantly reduced in the intervention group during the procedure of heel blood collection (P<0.05).

CONCLUSIONS

Maternal voice stimulation helps to reduce procedural pain and maintain stable vital signs in neonates.

Exposure to human voices has beneficial effects on preterm infants in the neonatal intensive care unit

We reviewed the literature up to March 2016 on the effects of nonmaternal voices on preterm infants' clinical outcomes. Of the 11 studies that met the inclusion criteria, 10 focused on short-term outcomes and one looked at long-term effects. The studies mainly showed that vocal stimuli increased preterm infants' stability in terms of heart rate, respiratory rate, oxygen saturation and behavioural measures. Improvements in feeding skills were also reported. The methods and the measures used in the studies were heterogeneous, making it difficult to draw reliable conclusions.

CONCLUSION

Vocal stimuli increased preterm infants' stability, but further studies are needed.

Noise in the neonatal intensive care unit: a new approach to examining acoustic events

INTRODUCTION

Environmental noise is associated with negative developmental outcomes for infants treated in the neonatal intensive care unit (NICU). The existing noise level recommendations are outdated, with current studies showing that these standards are universally unattainable in the modern NICU environment.

STUDY AIM

This study sought to identify the types, rate, and levels of acoustic events that occur in the NICU and their potential effects on infant physiologic state.

MATERIALS AND METHODS

Dosimeters were used to record the acoustic environment in open and private room settings of a large hospital NICU. Heart and respiratory rate data of three infants located near the dosimeters were obtained. Infant physiologic data measured at time points when there was a marked increase in sound levels were compared to data measured at time points when the acoustic levels were steady.

RESULTS

All recorded sound levels exceeded the recommended noise level of 45 decibels, A-weighted (dBA). The 4-h Leq of the open-pod environment was 58.1 dBA, while the private room was 54.7 dBA. The average level of acoustic events was 11-14 dB higher than the background noise. The occurrence of transient events was 600% greater in the open room when compared to the private room. While correlations between acoustic events and infant physiologic state could not be established due to the extreme variability of infant state, a few trends were visible. Increasing the number of data points to overcome the extreme physiologic variability of medically fragile neonates would not be feasible or cost-effective in this environment.

CONCLUSION

NICU noise level recommendations need to be modified with an emphasis placed on reducing acoustic events that disrupt infant state. The goal of all future standards should be to optimize infant neurodevelopmental outcomes.

Unlike Kangaroo care, mechanically simulated Kangaroo care does not change heart rate variability in preterm neonates

BACKGROUND

While numerous positive effects of Kangaroo care (KC) have been reported, the duration that parents can spend kangarooing is often limited.

AIM

To investigate whether a mattress that aims to mimic breathing motion and the sounds of heartbeats (BabyBe GMBH, Stuttgart, Germany) can simulate aspects of KC in preterm infants as measured by features of heart rate variability (HRV).

METHODS

A within-subject study design was employed in which every routine KC session was followed by a BabyBe (BB) session, with a washout period of at least 2 h in between. Nurses annotated the start and end times of KC and BB sessions. Data from the pre-KC, KC, post-KC, pre-BB, BB and post-BB were retrieved from the patient monitor via a data warehouse. Five time-domain features of HRV were used to compare both types of intervention. Two of these features, the percentage of decelerations (pDec) and the standard deviation of decelerations (SDDec), were developed in a previous study to capture the contribution of transient heart rate decelerations to HRV, a measure of regulatory instability.

RESULTS

A total of 182 KC and 180 BabyBe sessions were analyzed in 20 preterm infants. Overall, HRV decreased during KC and after KC. Two of the five features showed a decrease during KC, and all features decreased in the post-KC period (p ≤ 0.01). The BB mattress as employed in this study did not affect HRV.

CONCLUSION

Unlike KC, a mattress that attempts to mimic breathing motion and heartbeat sounds does not affect HRV of preterm infants.

A description of externally recorded womb sounds in human subjects during gestation

Objective

Reducing environmental noise benefits premature infants in neonatal intensive care units (NICU), but excessive reduction may lead to sensory deprivation, compromising development. Instead of minimal noise levels, environments that mimic intrauterine soundscapes may facilitate infant development by providing a sound environment reflecting fetal life. This soundscape may support autonomic and emotional development in preterm infants. We aimed to assess the efficacy and feasibility of external non-invasive recordings in pregnant women, endeavoring to capture intra-abdominal or womb sounds during pregnancy with electronic stethoscopes and build a womb sound library to assess sound trends with gestational development. We also compared these sounds to popular commercial womb sounds marketed to new parents.

Study design

Intra-abdominal sounds from 50 mothers in their second and third trimester (13 to 40 weeks) of pregnancy were recorded for 6 minutes in a quiet clinic room with 4 electronic stethoscopes, placed in the right upper and lower quadrants, and left upper and lower quadrants of the abdomen. These recording were partitioned into 2-minute intervals in three different positions: standing, sitting and lying supine. Maternal and gestational age, Body Mass Index (BMI) and time since last meal were collected during recordings. Recordings were analyzed using long-term average spectral and waveform analysis, and compared to sounds from non-pregnant abdomens and commercially-marketed womb sounds selected for their availability, popularity, and claims they mimic the intrauterine environment.

Results

Maternal sounds shared certain common characteristics, but varied with gestational age. With fetal development, the maternal abdomen filtered high (500–5,000 Hz) and mid-frequency (100–500 Hz) energy bands, but no change appeared in contributions from low-frequency signals (10–100 Hz) with gestational age. Variation appeared between mothers, suggesting a resonant chamber role for intra-abdominal space. Compared to commercially-marketed sounds, womb signals were dominated by bowel sounds, were of lower frequency, and showed more variation in intensity.

Conclusions

High-fidelity intra-abdominal or womb sounds during pregnancy can be recorded non-invasively. Recordings vary with gestational age, and show a predominance of low frequency noise and bowel sounds which are distinct from popular commercial products. Such recordings may be utilized to determine whether sounds influence preterm infant development in the NICU.

Do mothers sound good? A systematic review of the effects of maternal voice exposure on preterm infants' development

Preterm infants are hospitalized in the Neonatal Intensive Care Unit (NICU) and are precociously separated from their mothers. Although developmental care interventions are meant to facilitate mother-infant bonding, physical contact is not always possible. Maternal voice exposure has been proposed as a way to foster maternal closeness and support postnatal bonding. Here we present a systematic review on maternal voice effects on preterm infants' development. Literature search occurred on 4 databases (PubMed, Scopus, Web of Science and CINAHL). Preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines have been adopted and standardized quality appraisal has been carried on. Wide differences emerged in infants' characteristics and maternal voice exposure methods. Inconsistency emerged for physiological outcomes (e.g., heart rate variability, oxygen saturation, number of critical alarm events), whereas a robust pattern of findings emerged for feeding behaviors, as well as cognitive and neurobehavioral development. Maternal voice appears to be a non-noxious intervention, which is consistent with developmental care and which can be embedded in developmental care strategies.

Effect of mother's voice on neonatal respiratory activity and EEG delta amplitude

While the influence of the mother's voice on neonatal heart-rate response and its relevant activity on cerebral cortex and the autonomic nervous system (ANS) are well known, few studies have assessed its influence on respiratory activity. We investigated the relationship among the respiration rate, the delta wave amplitudes through electroencephalography, and the basal state of ANS through the respiratory variability index while 22 full-term neonates hear their mother's voice and an unknown voice. It was found that when respiratory variability was large, a transient (<5 s) change in respiration rates was observed in response to an unknown voice, while a greater increase in the delta wave amplitude was observed in the frontal lobe than the parietal one in response to the mother's voice. Conversely, when respiratory variability was small, a sustained increase (>10 s) in respiration rates was observed in response to the mother's voice, while a greater increase in the delta wave amplitude was found in both the frontal and parietal lobes. These results suggest that the basal state of ANS influences the latency of increases in respiration rates. Furthermore, induced by the mother's voice, transient increases in respiration rates are reduced in association with frontal lobe activity, and sustained increases in respiration rates are promoted in association with frontal and parietal lobe activities.

Effects of Covering the Eyes versus Playing Intrauterine Sounds on Premature Infants' Pain and Physiological Parameters during Venipuncture

BACKGROUND

There is a need to assess the impact of initiatives to reduce exposure to environmental light and sound in preterm infants undergoing painful interventions in neonatal intensive care units.

OBJECTIVES

In this study, we aimed to identify the effect of covering the eyes and playing the intrauterine ambient sounds on premature infants' pain and physiological parameters during venipuncture.

METHODS

This was a randomized controlled trial. Ninety-four preterm infants were randomly divided into three groups: intrauterine sounds (n=32), covered eyes (n=32), and control (n=30) groups. Data were collected on the Preterm Infant Information Form, Preterm Infant Follow-up Form, and Neonatal Infant Pain Scale (NIPS), used to assess pain.

RESULTS

A significant difference was found between the intervention and control groups' NIPS score after venipuncture, which was primarily due to covered eyes' group. No significant difference was found between the intervention and control groups' NIPS score during venipuncture. In addition, no significant difference was found between the intervention and control groups of infants physiological parameters before, during, and after venipuncture. The practice of covering preterm infants' eyes during venipuncture positively affected their pain scores after venipuncture.

CLINICAL IMPLICATIONS

The effect of covering the eyes and playing the intrauterine ambient sounds in preterm infants may be recommended as simple, safe, and supportive stimuli that facilitate positive effects during painful procedures.

Effect of a mother's recorded voice on emergence from general anesthesia in pediatric patients: study protocol for a randomized controlled trial

BACKGROUND

Emergence delirium is a behavioral disturbance after general anesthesia in children and may distress both the patients and the primary caregivers, such as parents and medical staff, looking after the patients. Various medical and emotional interventions have been investigated to reduce emergence delirium; however, none are completely effective. This trial intends to assess whether the mother's recorded voice can reduce this adverse post-anesthesia event and facilitate arousal from general anesthesia.

METHODS/DESIGN

This is a prospective, double-blind, single-center, parallel-arm, superiority, randomized controlled trial to be conducted in participants aged 2-8 years who are undergoing elective surgery requiring general anesthesia. Participants will be randomly assigned to one of two groups: those who are stimulated to wake up by listening to their mother's recorded voice (maternal group, n = 33) or a stranger's voice (stranger group, n = 33) during anesthetic emergence. The primary outcome is the initial emergence delirium score in the post-anesthesia care unit (PACU). The secondary outcomes are hemodynamic parameters, including heart rate and mean blood pressure, the duration of time between the cessation of anesthetics and a BIS level of 60, 70 and 80, eye-opening or purposeful movement time, extubation time, total consumption of analgesics, PACU stay time, emergence delirium and pain scores during the PACU stay.

DISCUSSION

This is the first randomized controlled trial to investigate the effect of a mother's recorded voice during emergence on the pediatric emergence profile after general anesthesia. It may provide prophylactic treatment options to decrease emergence delirium and enhance arousal from general anesthesia.

TRIAL REGISTRATION

ClicnicalTrials.gov, ID: NCT02955680 . Registered on 2 November 2016.

Systematic review of maternal voice interventions demonstrates increased stability in preterm infants

We systematically reviewed how effectively maternal voice interventions supported the clinical outcomes and development of preterm infants. A total of 512 preterm infants were included in 15 studies with different designs, from January 2000 to July 2015. Live and recorded maternal voice interventions were associated with the physiologic and behavioural stabilisation of preterm infants, with fewer cardiorespiratory events, but the evidence was insufficient to evaluate the long-term effects. Well-defined determinants and clear setting conditions are needed for such interventions.

CONCLUSION

Further research that investigates the long-term efficacy and effects of live maternal voices on preterm infant development is needed.

A prospective observational cohort study of exposure to womb-like sounds to stabilize breathing and cardiovascular patterns in preterm neonates

PURPOSE

We exposed premature infants to womb-like sounds to evaluate such exposure on breathing and cardiovascular patterns. We hypothesized that these sounds would reduce apnea and intermittent hypoxemia, enhance parasympathetic outflow, and improve cardiovascular patterns.

METHODS

A total of 20 cases and 5 control infants at ≤32-36 weeks corrected gestational age participated in a prospective observational cohort study. Twenty-four hours of continuous ECG, respiratory and oxygen saturation data were collected in all infants. Womb-like sounds were played intermittently in 6-hour blocks. Salivary samples were collected at study beginning and end for cortisol. Apnea, intermittent hypoxemia, and bradycardia were evaluated, and heart rate variability was assessed by time domain and spectral techniques.

RESULTS

Intermittent hypoxemia and bradycardia significantly declined after sound exposure. No significant differences in apnea, cortisol levels, or heart rate variability were evident among the study infants.

CONCLUSIONS

Exposing premature infants to womb-like sounds has the potential to reduce hypoxemic and bradycardic events, and be used as an intervention to stabilize breathing and cardiac control in preterm infants.

Auditory Exposure in the Neonatal Intensive Care Unit: Room Type and Other Predictors

OBJECTIVE

To quantify early auditory exposures in the neonatal intensive care unit (NICU) and evaluate how these are related to medical and environmental factors. We hypothesized that there would be less auditory exposure in the NICU private room, compared with the open ward.

STUDY DESIGN

Preterm infants born at ≤ 28 weeks gestation (33 in the open ward, 25 in private rooms) had auditory exposure quantified at birth, 30 and 34 weeks postmenstrual age (PMA), and term equivalent age using the Language Environmental Acquisition device.

RESULTS

Meaningful language (P < .0001), the number of adult words (P < .0001), and electronic noise (P < .0001) increased across PMA. Silence increased (P = .0007) and noise decreased (P < .0001) across PMA. There was more silence in the private room (P = .02) than the open ward, with an average of 1.9 hours more silence in a 16-hour period. There was an interaction between PMA and room type for distant words (P = .01) and average decibels (P = .04), indicating that changes in auditory exposure across PMA were different for infants in private rooms compared with infants in the open ward. Medical interventions were related to more noise in the environment, although parent presence (P = .009) and engagement (P  = .002) were related to greater language exposure. Average sound levels in the NICU were 58.9 ± 3.6 decibels, with an average peak level of 86.9 ± 1.4 decibels.

CONCLUSIONS

Understanding the NICU auditory environment paves the way for interventions that reduce high levels of adverse sound and enhance positive forms of auditory exposure, such as language.

Language and hearing outcomes of preterm infants

Multiple factors including degree of prematurity, neonatal morbidities, illness severity, hearing status, gender, language environment in the neonatal intensive care unit and in the home, maternal education level, social and environmental status of the family, and access to early intervention all contribute to the language outcomes of extremely preterm infants with and without hearing loss. Early screening, early diagnosis, and early intervention services by 6 months of age are necessary to optimize the language outcomes of preterm infants with permanent hearing loss. There is increasing evidence of the potential for improved language skills with increasing age of extreme preterm infants and infants with hearing loss.

Enhanced attention to speaking faces versus other event types emerges gradually across infancy

The development of attention to dynamic faces versus objects providing synchronous audiovisual versus silent visual stimulation was assessed in a large sample of infants. Maintaining attention to the faces and voices of people speaking is critical for perceptual, cognitive, social, and language development. However, no studies have systematically assessed when, if, or how attention to speaking faces emerges and changes across infancy. Two measures of attention maintenance, habituation time (HT) and look-away rate (LAR), were derived from cross-sectional data of 2- to 8-month-old infants (N = 801). Results indicated that attention to audiovisual faces and voices was maintained across age, whereas attention to each of the other event types (audiovisual objects, silent dynamic faces, silent dynamic objects) declined across age. This reveals a gradually emerging advantage in attention maintenance (longer HTs, lower LARs) for audiovisual speaking faces compared with the other 3 event types. At 2 months, infants showed no attentional advantage for faces (with greater attention to audiovisual than to visual events); at 3 months, they attended more to dynamic faces than objects (in the presence or absence of voices), and by 4 to 5 and 6 to 8 months, significantly greater attention emerged to temporally coordinated faces and voices of people speaking compared with all other event types. Our results indicate that selective attention to coordinated faces and voices over other event types emerges gradually across infancy, likely as a function of experience with multimodal, redundant stimulation from person and object events. (PsycINFO Database Record